Metamath Proof Explorer


Theorem resvval2

Description: Value of nontrivial structure restriction. (Contributed by Thierry Arnoux, 6-Sep-2018)

Ref Expression
Hypotheses resvsca.r ⊢ R = W ↾ 𝑣 A
resvsca.f ⊢ F = Scalar ⁡ W
resvsca.b ⊢ B = Base F
Assertion resvval2 ⊢ ¬ B ⊆ A ∧ W ∈ X ∧ A ∈ Y → R = W sSet Scalar ⁡ ndx F ↾ 𝑠 A

Proof

Step Hyp Ref Expression
1 resvsca.r ⊢ R = W ↾ 𝑣 A
2 resvsca.f ⊢ F = Scalar ⁡ W
3 resvsca.b ⊢ B = Base F
4 1 2 3 resvval ⊢ W ∈ X ∧ A ∈ Y → R = if B ⊆ A W W sSet Scalar ⁡ ndx F ↾ 𝑠 A
5 iffalse ⊢ ¬ B ⊆ A → if B ⊆ A W W sSet Scalar ⁡ ndx F ↾ 𝑠 A = W sSet Scalar ⁡ ndx F ↾ 𝑠 A
6 4 5 sylan9eqr ⊢ ¬ B ⊆ A ∧ W ∈ X ∧ A ∈ Y → R = W sSet Scalar ⁡ ndx F ↾ 𝑠 A
7 6 3impb ⊢ ¬ B ⊆ A ∧ W ∈ X ∧ A ∈ Y → R = W sSet Scalar ⁡ ndx F ↾ 𝑠 A